All. Answering my own question, who got single breasted and who got double breasted Mundirs? I came across the info below on the internet. I hope it’s of interest to forum members.

Short Description of Mundirs for Personnel of the NKVD of the USSR

1. Mundir Single Breasted (Organs and Militia):

a. For General Commissars and Commissars of State Security, from diagonal or tufted wool of steel colour. Piping on the collar, front, cuffs and leaf pockets in cornflower colour. Gilded buttons. Stitched in accordance with pictures 28 & 29.
b. For senior and middle ranking staff, the cloth is khaki. Piping is as for Commissars. Gilded buttons. Stitched as per picture 30.
c. For junior staff and privates from half-breasted khaki cloth. For junior staff cornflower piping on the collar and cuffs. For privates, no piping. Brass buttons. Cornflower gorgets for junior staff with silver stripe, for privates bare.

2. Mundir Double Breasted (Military):

a. For Generals, from wave green tufted wool. Piping as for Commissars; green for Border Guards, cornflower for Internal Troops. Gilded buttons. Stitched in accordance with pictures 29.
b. For senior and middle ranking staff, khaki wool. Piping is as for Generals. Gilded buttons. Stitched as per picture 30.
c. For junior staff and privates from half-breasted khaki cloth. For junior staff piping on the collar and cuffs and gorgets in green for Border Guards and maroon for Internal Troops. For privates, no piping. Brass buttons. Gorgets for junior staff with gold stripe, for privates bare. Brass buttons

Notes:

1. For all ranks of the Militia mundirs are dark blue, piping turquois.
2. Sewing on mundirs with gold plated epaulettes – gilded.
3. Sewing on mundirs with silver plated epaulettes – silvered.
4. Buttons on mundirs for junior staff and privates of the Militia are from white metal.

Here is my newest find. A mundir for a private of NKVD Military Forces. The epaulettes are repros. I need to find gorgets.

Click to enlarge the picture